A Multi-Level Power Management Architecture for Battery-Powered SPAD Drivers with Supply Intrinsic Quenching and 10-ns Dead Time

Light detection and ranging (LiDAR) systems enable precise distance measurements by emitting laser and analyzing their reflections, which are critical for applications like robots, drones, and vehicles. Direct Time-of-Flight (dToF) LiDAR system is one of the most popular LiDAR systems to provide long distance with high accuracy and speed by measuring the time it takes for the pulsed laser to travel to an object and return. In the receiver of a dToF LiDAR system, Single- Photon Avalanche Diode (SPAD) is typically used due to its exceptional sensitivity to light. By reversely biasing the SPAD beyond its breakdown voltage, a high electrical field is generated, which causes a self-sustaining avalanche of carriers and introduces a current pulse when catching a photon. To stop the avalanche and recover, quenching is required through quickly reducing the bias voltage below the breakdown level. After that, hold-off time might or might not be necessary (depending on the type of SPAD) to stabilize the SPAD and avoid self- triggering. Then the bias voltage of SPAD is recovered to prepare for the next avalanche. The total time needed from quenching, hold-off, to recovery is defined as the “dead time”. A shorter dead time enables the SPAD to recover faster after each detection, making it more capable of handling higher photon fluxes without missing subsequent photons, thus increasing the dark count rate, detection efficiency, temporal resolution, and overall system throughput.